In a study led by Purdue University, researchers found that Vitamin D functions to reduce inflammation caused by immune cells, relevant to responses during severe COVID infection. "Because the Vitamin D receptor is expressed on immune cells and because these cells can synthesise the active Vitamin D metabolite. Vitamin D also has the potential to modulate adaptive immune responses," Dr Sanjay Kumar Gogia, Director, Internal Medicine, Fortis Hospital, Shalimar Bagh, told IANS.
Further, COVID has been particularly worse to older adults, people with obesity and hypertension -- again a group with deficiency in Vitamin D. Another study led by Bar-Ilan University in Safed, Israel, Vitamin D levels, prior to COVID infection, may increase severity of the disease as well risk of mortality. The study found that patients with Vitamin D deficiency (less than 20 ng/mL) were 14 times more likely to have severe or critical cases of COVID than those with more than 40 ng/mL.
The US Centers for Disease Control and Prevention (CDC), recently stated that over 75 percent of people who died due to COVID had comorbidities like uncontrolled hypertension, diabetes, renal diseases and obesity. "Low Vitamin D levels have been associated with an increased risk of community-acquired pneumonia in older adults and children," Gogia said. He cited that in a meta-analysis of randomised clinical trials, vitamin D supplementation was shown to protect against acute respiratory tract infection.
However, in few clinical trials, administering high doses of Vitamin D to critically ill patients with vitamin D deficiency (but not COVID-19) did not reduce the length of the hospital stay or the mortality rate when compared to placebos. "The rationale for using Vitamin D is based largely on immunomodulatory effects that could potentially protect against COVID-19 infection or decrease the severity of illness," Gogia noted.